[Cosmo-torun] [astro-ph/0510760] Constraints on changes in fundamental constants from a cosmologically distant OH absorber/emitter

Boud Roukema boud w astro.uni.torun.pl
Śro, 4 Sty 2006, 14:13:06 CET


On Wed, 4 Jan 2006, Andrzej Marecki wrote:

> Better late than never... Only now I have spotted this:
> http://de.arxiv.org/abs/astro-ph/0510760

Hmmm, looks like both sides of the road in Pune - TIFR (radio) and IUCAA
(optical) are working together to test the claims of fine structure constant

The most recent claim i see is:

Murphy, Flaumbaum, Webb et al claim
dalpha/alpha= (-0.57 +/- 0.11)x10^{-5}  = -(6 \pm 1) *10^-6

0510760 is Nissim Kanekar (TIFR graduate) et al.  getting an upper limit on
(Delta alpha)/alpha < 6.7 \times 10^{-6}

while more than a year earlier, Srianand (IUCAA) et al. got :
over 0.4<z<2.3 :
 \Delta\alpha/\alpha = (-0.06+/-0.06) x 10^{-5} = -(6 \pm 6) * 10^-7

Well, IMHO -6e-6 < + 6.7e-6 so if the signs are correct, then the OH
constraints (Nissim Kanekar et al.)  certainly don't rule out the
detection claim. And if the sign convention is wrong, then we still
have 6e-6 < 6.7e-6, which is still consistent.

On the other hand, Srianand et al. get one order of magnitude better:

 -(6 \pm 6) * 10^-7

Figure 3 of Srianand et al. 0402177 is fairly clear and it looks like the
statistics against the claimed Murphy et al. result are quite robust.


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